History. Farm labourers and others were on quarterly contracts since mid 1450s. "Hiring Fairs " on Quarter Days (Christmas day was one quarter day, when debts etc were due for payment hiring new staff etc , so system pre-dates the Modern Europeans in America.

1.BBC in UK has for many years 'employed' many 'staff' on 13 week contracts. Renews if necessary , one person worked out 36 years that way. Always 'shedable' at end of 13 weeks , Actor carries his own insurance for health illness and Professional Liability to main company. Its a way of life.
2 As a (non-IT) engineer I am now into seventh year of short term contracts for one UK company. Suits me, I work only the hours I want to work. Life Ok for reward. However I base all things on Salary in year to myself through the MY Limited Company (a private Incorporation) billing the UK Client Company. This allows me to get insurance as easy to get insurance for company employees via company, but maybe no so as 'persons'. Tax saving is little, depends on how much you leave in company, but taking out say 80% billing as salary is OK in UK. There are up front yearly charges as insurance / IT stuff etc to buy before you can enter into a reasonable contract , so you need to cover that in a 'minimum expected hours' or retainer clause. P.S. I do IT as well , but that is not what they pay for.

I often wondered why USA constitution did not follow the established and known formulae of most European states/kingdoms/dictatorships origin in that "treason" has two grades "High Treason" and "Petty Treason" ,or big and little treason. It avoids conflicts of jury disagreements on grade.

similar corporate story. 4000+machines, 30% desktops circa 2000/2002 XP Pentium 4s, adequate for word documentation and spreadsheets, old corporate programs need to be upgraded/re-written from 1998 libraries; 60% 2004 laptops with XP Office 2010, new employees & machine failures put onto laptops win 7, MS office 2010, as basis of a slow upgrading. Change scheduled, funds allowing, to go all Win 7 in 2014 onwards with new laptops but company heavily indebted, so that is not a small beans rounding error in total even when compared to employee remuneration plus costs, it is real cash spend from borrowed money.

I use different browsers for different jobs.
  Firefox , tied down securely for strange places and work investigations( mainly China and Russia banks) and Slashdot (!) but I do not try to work with my own bank due 'pop ups', Java etc
  Chrome for 'less secure browsing' and may own banking (from a live Linux to Internet over a wired connection, Java enabled)
  IE for intranet at work ( They standardized on IE, and it shows and hurts.)
  IE for Windows updates (not possible on FF or Chrome!)

Sometimes you do in a job that which is immoral (like kill random people as a soldier or whatever) but you do it in the name of a 'higher good'.
From my point of view, with some of above experience, you remember them in your dreams and nightmares for the rest of your life. You are excused legally, but your conscience does not let it go.